Usually what happens is inflation of the countries currency, which means that your pension is not increasing the more you work but most of the time decreasing. To protect from this is hard, as the country does not dictate its value. Also, the life span of people has increased. There are many factors to why pensions are a bit of a scam, and I use that term vaguely as it is not a real scam, but more of an "I paid 25$ per month for 65 years, that means I need to be paid 600$ per month until I die", but the reality is that the 25$ paid in your 20s may be worth 3.5$ in your 60s. In my opinion, a universal pension would help a lot, but that isn't able in capitalism (Which is good in my opinion), but a universal standard pension could be a solution.
The universal standard pension would be like a minimum salary equivalent plus a % of your tax payments for the pension. For argument's sake let's say you would get 250$ standard pension, but since you put aside a lot you get 250$ plus on it due to your possibilities.
That's my idea, an universal pension would be cool.